逐远：离得越远箭越重

 fx-farshot

-- @file FarShot.lua
-- 逐远 —— 箭飞一步涨一点伤害，越远越疼

local FarShot = {}

local CONST = {
    ARROW_SPEED   = 280,
    DMG_PER_STEP  = 0.033,
    DMG_BASE      = 10,
    ARROW_CD      = 0.8,

    COLOR_FAR     = "#78a8d0",
    COLOR_DEEP    = "#284858",
    COLOR_GHOST   = "#c8e0f0",

    ZORDER_ARROW  = 133,
    ZORDER_FX     = 135,
    AUTOINC_BASE  = 1061000,
}

local _arrows    = {}
local _cdLeft    = 0
local _scheduler = nil
local _autoInc   = 0

local function GenID(prefix)
    _autoInc = _autoInc + 1
    return string.format("%s_%d", prefix or "FRS",
        CONST.AUTOINC_BASE + _autoInc)
end

local function GetActorPos(id)
    if not id then return nil end
    local x = SL:GetValue("ACTOR_POSITION_X", id)
    local y = SL:GetValue("ACTOR_POSITION_Y", id)
    if not x or not y then return nil end
    return { x = x, y = y }
end

local function SafeRemove(node)
    if node and not GUI:Widget_IsNull(node) then
        GUI:removeFromParent(node)
    end
end

local function ShowTip(msg)
    if msg and msg ~= "" then SL:ShowSystemTips(msg) end
end

local function CalcDist(d)
    return CONST.DMG_BASE + math.floor(d * CONST.DMG_PER_STEP)
end

function FarShot.Shoot()
    if _cdLeft > 0 then return end
    local myID = SL:GetValue("USER_ID")
    local mp = GetActorPos(myID)
    if not mp then return end
    _cdLeft = CONST.ARROW_CD
    SL:PlayShootFx(myID)
    SL:TipAboveMe("射！")
end

-- 定时器：弹道推进与逐远结算
if not _scheduler then
    _scheduler = SL:Schedule(function(dt)
        _cdLeft = math.max(0, _cdLeft - dt)
        for i = #_arrows, 1, -1 do
            local a = _arrows[i]
            a.x = a.x + a.vx * dt
            a.dist = a.dist + a.vx * dt
            local tid = SL:GetValue("MARK_TARGET_ID")
            local tp = tid and GetActorPos(tid)
            if tp and math.abs(a.x - tp.x) <= 20 then
                local dmg = CalcDist(a.dist)
                SL:ActorHurt(tid, dmg)
                SL:TipAbove(tid, "-" .. dmg)
                if dmg > 15 then
                    SL:PlayFarHitFx(tid)
                end
                table.remove(_arrows, i)
                if SL:GetValue("ACTOR_DEAD", tid) then
                    ShowTip("它倒了——千里之外一箭穿心")
                end
            elseif a.x > 700 or a.x < -20 then
                table.remove(_arrows, i)
            end
        end
    end, 0.02)
end

SL:ScheduleOnce(function()
    SL:BindDebugButton("逐远", function()
        FarShot.Shoot()
    end)
    ShowTip("技能已加载: 逐远 (调试按钮触发)")
end, 1.0)

function FarShot.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    _arrows = {}
end

return FarShot